The correct answer is D) allow voluntary actions to resolve it.
President's Hoover overall plan to deal with the Great Depression was to allow voluntary actions to resolve it.
His work to resolve the economic crises focused on indirect relief from private companies, the states, and volunteerism. But the economic problems became worse and people demanded the federal intervention and spending but Hoover denied it. He didn't want to act in fixing prices, manipulating the value of the currency or controlling businesses because he considered that those were measures of socialists. Meanwhile, American people still was facing terrible problems due to unemployment and the bankruptcy of the banks.